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2 years ago

Which equation is true?

2 answers:

6 0

Answer: The first one (12+17)-9=(23-7)+4

Explanation: First add 12 and 17 because it’s in parentheses which will give you 29. Then subtract 9 to get 20. After that, solve the problem on the right side of the equal sign, therefore 23-7 is 16. Lastly, add the 4 to 16 to get 20 which means that this equation is equal because (12+17)-9 does give you the same answer as (23-7)+4 which in conclusion means it’s a true equation.

Vlad1618 [11]2 years ago

4 0

Answer:

the third one

Step-by-step explanation:

You might be interested in

Solve equations -8x=88

Alexxx [7]

ANSWER:X=-11

Explanation

3 0

3 years ago

(r-3)(r-1) Help me please!!!

madreJ [45]

Answer:

= r²−4r+3

Step-by-step explanation:

(r - 3) (r - 1)

(r x r) + (r x -1) + (-3 x r) + (-3 x -1)

r² + - r - 3r + 3

= r²−4r+3

5 0

2 years ago

The heights of the trees in a forest are normally distributed, with a mean of 25 meters and a standard deviation of 6 meters. Wh

Alla [95]

Answer:

2.3%

Step-by-step explanation:

The formula to convert x into z distribution is

$z=\frac{x-\mu}{\sigma}$

Where z is the test statistic

x is what we are looking for (in this case 37)

$\mu$ is the mean (in this case, it is 25)

$\sigma$ is the standard deviation (we have 6)

Plugging these into the formula, we get:

$z=\frac{x-\mu}{\sigma}\\z=\frac{37-25}{6}\\z=2$

Thus we can say we want $P(z\geq 2)$

Note: $P(z\geq a)=1-P(z\leq a)$

The table given is for any z where $P(z\leq a)$

Thus, now we have:

$P(z\geq 2)\\=1-P(z\leq 2)\\=1-0.9772\\=0.0228\\$

0.0228 into percentage is 0.0228 * 100 = 2.28%

Rounded, we get 2.3%

Third answer choice is right.

3 0

3 years ago

Rosetta wants to estimate the percentage of people who rent their home. She surveys 250 individuals and finds that 48 rent their

Andreas93 [3]

Answer:

$0.192 - 1.645\sqrt{\frac{0.192(1-0.192)}{250}}=0.151$

$0.192 + 1.645\sqrt{\frac{0.192(1-0.192)}{250}}=0.233$

Step-by-step explanation:

Information given

$X= 48$ number of people who rent their home

$n= 250$ represent the sample size

$\hat p =\frac{48}{250}= 0.192$ represent the proportion of people who rent their home

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 90% of confidence, our significance level would be given by $\alpha=1-0.90=0.1$ and $\alpha/2 =0.05$ . And the critical value would be given by:

$z_{\alpha/2}=\pm 1.645$

The confidence interval for the mean is given by the following formula:

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

If we replace the values obtained we got:

$0.192 - 1.645\sqrt{\frac{0.192(1-0.192)}{250}}=0.151$

$0.192 + 1.645\sqrt{\frac{0.192(1-0.192)}{250}}=0.233$

3 0

3 years ago

Write the slope-intercept form of the equation of the line described by (−1, −1), parallel to y = −2x − 4

LuckyWell [14K]

Answer:

y = -2x - 3

Step-by-step explanation:

Slope intercept form of line is

y = mx + c

where

m is the slope and c is the y intercept

________________________________________

Given that line

y = −2x − 4

comparing it with y = mx + c

m = -2 and c = -4

Thus, slope of this line is -2

we also know that when two lines are parallel then their slopes are same

thus, slope of required line will be m = -2

___________________________________________

now let the equation of line passing through (-1,-1) be

y = mx + c

we have found m to be -2

using this in above equation we have

y = -2x + c

since (-1,-1) passes through the above line using x = -1 and y = -1

we have

-1 = -2*-1 + c

-1 = 2 + c

c = -1 - 2 = -3

using c = -3 in y = -2x + c

we have

equation of line as

y = -2x - 3 in slope intercept form.

7 0

2 years ago